What it is used for
- Uncomplicated urinary tract infections (cystitis), often as a single-sachet treatment
- Sometimes used for certain resistant urinary infections under specialist advice
How it works
Fosfomycin is an antibiotic that stops bacteria from building their cell walls. It concentrates in the urine, which makes it useful for bladder infections. It is often given as a single dose for simple urinary infections.
How it is taken
Most commonly comes as a powder (granules) in a sachet that is dissolved in water and taken by mouth; an injectable form is used in hospital. Take it exactly as your doctor or pharmacist directs and follow the label. The oral form is often taken on an empty stomach, sometimes at bedtime after emptying the bladder.
No doses here on purpose. The right strength and schedule depend on you — only a doctor or pharmacist should set them. Always follow your prescription and the label.
Common side effects
- Diarrhoea
- Nausea
- Headache
- Dizziness
- Mild stomach upset
- Vaginal irritation or thrush
Serious effects — get help
- Severe allergic reaction with swelling or breathing difficulty
- Severe, persistent or bloody diarrhoea
- Symptoms that do not improve or that worsen after treatment
If a reaction is severe — for example trouble breathing, swelling of the face or throat, or collapse — go to the nearest emergency room now or call your local emergency number. Do not wait for an online consultation.
Interactions to watch
- Metoclopramide and similar medicines that speed up the gut (may reduce its effect)
- Some antacids
- Other medicines should be reviewed by your pharmacist
Who should take care
- Tell your clinician if your symptoms do not improve after the single dose, as you may need further assessment
- Tell your clinician if you have kidney problems
- Discuss pregnancy or breastfeeding with your doctor or pharmacist
- Mention all other medicines you take
- Drink fluids as advised